Interesting possibility. It can work, but it will increase the rigging aspect involved.

Also keep in mind that the maximum capacity of a winch is only achieved when your winch line is on the first layer wrapped on the drum. So, to get that maximum capacity you would always need to unwind most of the line. When you get more wraps, the effective diameter of the drum increases which decreases the power provided.

Herb

__________________

__________________SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.

Do you think 17K (8500 x2) or the 15K are enough power for an 8500 lb sprinter? Snow, sand, getting over some difficult terrain (difficult for a sprinter). I think maxtrax would get us out of 90% of the situations we'd ever get in, but sliding off a trail in an area without cell service would be bad.

No issues with the rigging (rock climbers). I guess it comes down to whether the winch would be effective enough to warrant the weight and cutting of the bumper.

I guess more ideally, I'd have something removable that would fit into the rear receiver. But, I don't have enough experience with winching to know if front or rear is drastically more effective.

As the snatch block is double the winch capacity, they are matched for 20k lb. of pulling. If you have Class 5 receiver hitches on the front and back, you could store the winch inside the van or in an Aluminess box, then connect it front or rear as needed. It's still 100 lb., but has a handle on each end such that two people could split that load. The winch is for a 2" receiver (Class 3 or 4), while Class 5 can be 2" or 2.5", so you'd need the 2" Class 5 receiver. If you got the 2.5", you would need a square sleeve bushing to adapt the space.

I'm sure there are some drawbacks and that others will pitch in re. how efficient such a setup would be.

Of course, you could mount separate 10k lb. winch on front and rear and use the rigging, extra line, etc., wherever needed if you really felt that need.

If you aren't familiar with them, you might want to read about land anchors and also about airing down/on board air for airing up.

You lose a bit of distance pulley and 100 ft line, but that can be made up with an extra bit of tow rope.Anything I'm missing?

Other than loosing one half of your line length, and cutting line speed in half, it should work fine, (assuming all your attachement points are up to the added strain, including the recovery points on the van)...............

Be careful not to overstress the front bumper and frame by forgetting the force you are applying by using a pulley. If you can truly tolerate a 15K lb winch, I think an 8K lb with pulley will be fine in theory. Either way, in practice, when you are operating at really heavy forces, you need to be careful not to damage your vehicle. Even at 8K trying to pull out a jeep stuck in mud up to floor boards, my vehicle slides towards them before they to me. Need a second vehicle behind me anchoring me with tow strap. If you are not straight on, for example, imagine the torque you are applying to your frame.

+1 for more modest (and lighter) winches, with pulley for crunch time.

Keep in mind that a winch's rated capacity is also only good for the first wrap on the drum. 8500lbs best case scenario, with the line all the way out. With a block, that 20' (random guess) of rope on the first wrap is only moving you 10'. Just something to think about. If you really feel you're going to need the winch I'd go for something heavier personally.

I split the difference between the two you proposed. A warn zeon 12s (80' Synthetic rope), 80lbs, with an arb snatch block. You could argue that a 12k winch is undersized for a big heavy rig.

I've read that a good rule of thumb is twice the GVWR, which would be around 17K lbs for a loaded Sprinter 2500. Warn's website states to use a 1.5 factor. That would be a range of 12.8k to 17k lbs capacity. If you're using a snatch block at 12K lbs, that 24K lbs of pulling power.

With that, are you saying that you should factor in the number of wraps on the drum to account for the GVWR? Or, is that an FYI in that pulling power decreases with increased line length?